The purpose of this study is to use the recently derived cDNA clone for human pancreatic mucin and monoclonal antibodies against the core protein to investigate mucin expression in epithelial cells from normal and mutant CFTR genes on mucin expression and post-translational processing will be examined in epithelial cell lines expressing the mucin and CFTR genes. In addition, complementation assays will examine the effect on mucin expression of inserting the normal CFTR into cell lines expressing mutant CFTR. A mouse transgenic for this mucin is available for cross breeding with CFTR transgenic mice as they become available. Finally, the cis acting elements and trans actin factors involved in regulating mucin gene expression will also be evaluated in CF and non CF epithelial cells.